The Antarctic Ice Sheet is More Vulnerable to Carbon Dioxide Levels Than Previously Thought

Antarctic ice may be far more vulnerable to climate change than anyone expected. Scientists have created a new climate reconstruction of how Antarctica's ice sheets responded during the last period when atmospheric carbon dioxide (CO2) reached levels like those expected in 30 years, and found that the ice sheets may melt more quickly than expected.

In this latest study, the researchers analyzed a 3,735-foot sediment core from McMurdo Sound in order to reconstruct the Antarctic ice sheet's history. They wanted to examine the core to create a model that simulated conditions similar to those experienced to mid-Miocene. This was likely the last time atmospheric CO2 levels were slightly higher, at 500 parts per million (ppm), than the 400 ppm level reached just last year.

While CO2 levels may be at the same level as during the Miocene in the next 30 years, it doesn't mean that the ice sheets will melt in 30 years; understanding how the Antarctic ice sheets will respond, therefore, is a major goal for scientists.

In this case, the researchers were able to create a model to show the retreat of the Antarctic ice sheet. This showed that even small changes in atmospheric CO2 can cause shifts in the ice sheet.

"We know that the Antarctic ice sheet will eventually melt if we burn all known fossil fuel reserves, raising sea levels by over 100 feet," said Edward Gasson, one of the researchers, in a news release. "What these two studies show is that the Antarctic ice sheet is also vulnerable to much lower levels of carbon dioxide than we thought possible before."

The findings are published in two studies in the journal Proceedings of the National Academy of Scienceshere and here.